The present invention concerns photographic copying machines for copying originals of a long strip of originals. Typically, such copying machines are provided with an automated or semi-automated evaluating station where successive originals are evaluated with respect to their densities in three component colors and/or with respect to their position on the long strip of originals; alternatively, information representing the result of such evaluation may have been earlier generated and marked onto the originals themselves or onto a data-carrier strip which travels in synchronism with the strip of originals, in which case the evaluating station of the machine is mainly a code reader which reads the results of the earlier evaluation. Such copying machines are furthermore provided with automatic exposure constrol systems controlled by the data generated as a result of the aforementioned evaluation, and are provided with an exposure system, projection optics for projecting an image of each original onto photographic paper or other copying medium guided along a predetermined path, and typically comprise an adjustable set of color filters for controlling the component colors and often a shutter for blocking exposure light intermediate successive copying operations.
Conventional photographic copying machines of the types referred to above have had their productivity brought up to as high as 12,000 copies per hour. Further increase in copying-machine productivity is extremely difficult to achieve, because the constituent operations involved in one copying cycle are nowadays already performed as quickly as a reasonable level of technology will permit. The duration of a copying cycle is mainly comprised of the time intervals required to advance the strip of originals and to advance the strip of copying paper, the time interval required for automated or semiautomated evaluation of each original, and the time interval required for the copying exposure per se. Although a machine productivity on the order of 12,000 copies per hour may appear quite considerable, during certain seasons of the year photographic processing laboratories find this rate of productivity not sufficient to keep up with customer demand.